Field of the Invention
The present invention relates to a method and apparatus for the generation and transmission of predeterminable complex pressure surges to the fluid system of the inner ear, in order to achieve intermittent compression of the fluid system in the labyrinth of the inner ear.
More specifically the invention relates to a method and apparatus for the generation and transmission of complex pressure surges to the fluid system of the inner ear, this fluid system comprising an outer fluid chamber (perilymphatic space) provided with inlet and outlet, which entirely surrounds an inner fluid chamber (endolymphatic space), the fluid volume therein regulating the hearing ability of the ear in order, through intermittent compression of said inner chamber, to reduce any impairment of the hearing which may exist due to expansion of said chamber caused by too large a volume of fluid in said inner chamber.
The apparatus provided according to the invention can be used with advantage to influence the relation between the two fluid systems of the inner ear (perilymphatic and endolymphatic) when the membranous labyrinth is swollen (Meniere's disease).
The invention can also be used to study the effects of various types of pressure waves, for instance, infra-sound on the function of the inner ear in animals and humans.
It has been established that alterations in the endolymphatic space affect the functioning of the ear and that certain diseases are attributable to such alterations. Examples are Meniere's disease, characterised by symptoms such as loss of hearing, dizziness, tinnitus, feelings of the ear being blocked, etc. This often results in complete inability to work, partially due to impaired functioning of the ear but primarily because of the psychological effect which in some cases may be drastic. Surgical treatment of the endolymphatic sac has been attempted but the results have either been short-lived or non-existent.
In 1908 British Pat. No. 10,695 proposed a vibratory apparatus for treating pathological states in the tympanic membrane to relieve "head noise" and other undefined forms of impaired hearing. According to the description of this British Patent, both positive and negative pressure are used which, as is clear from the following description of the invention, cannot solve the present problem.
There has also recently been discussion of influencing the hydrodynamic systems of the inner ear by applying a pressure alteration in the auditory meatus. The device utilised comprised first means for generating a static pressure level, second means for varying the static pressure level, and third means for connecting the first and second means to the auditory canal. Although this proposal touches upon the idea of influencing the hydrodynamic system inside the ear, it offers no practical solution of the existing problem since the necessary build-up of special complex pulses, which is proposed according to the present invention, cannot be inferred from this publication.